There is provided a prober provided with a plurality of inspection chambers. Each inspection chambers includes: a probe card having a plurality of probes; a probe card holder configured to hold the probe card; a chuck top configured to place a cleaning wafer thereon; an aligner configured to drive the chuck top in a vertical direction when the probe card is cleaned using the cleaning wafer; a seal mechanism configured to allow a sealed space to be provided between the probe card holder and the chuck top; a pressure sensor configured to detect an internal pressure of the sealed space, which fluctuates with an operation of the chuck top driven by the aligner; and an electro-pneumatic regulator configured to control the internal pressure of the sealed space by performing an intake or exhaust operation with respect to the sealed space based on the internal pressure detected by the pressure sensor.